MadVapes and LiteCigUSA have the 510 disposables. I've never had a standard 510 auto batt but i hear that like other's they are sensitive to wind and sound and it's made them pretty unpopular compared to the manuals. I would suggest buying a 3 or 5 pack of the disposables at 10 bucks a piece because those ones are made differently (pneumatic) and will only turn on when you draw on them. The catch is they're supposed to only last for three charges (so far I've been using mine for a month no problem, many others report the same) so by buying a couple of them you end up with spare attys and a few
batteries that will probably last you a while, won't frustrate you with going off on their own and if you drip, you won't mind killing a battery that cost you so little.
Hope that helps!